Low small mesoporous peak cracking catalyst and method of using

ABSTRACT

This invention relates to the composition, method of making and use of a fluidized catalytic cracking (“FCC”) catalyst that is comprised of a new Y zeolite which exhibits an exceptionally low small mesoporous peak around the 40 Å (angstrom) range as determined by nitrogen adsorption measurements. FCC catalysts made from this new zeolite exhibit improved rates of heavy oil cracking heavy oil bottoms conversions and gasoline conversions. The fluidized catalytic cracking catalysts herein are particularly useful in fluidized catalytic cracking (“FCC”) processes for conversion of heavy hydrocarbon feedstocks such as gas oils and vacuum tower bottoms.

CROSS REFERENCE TO RELATED APP CATIONS

This Application claims the benefit of U.S. Application No. 61/339,928,filed Mar. 11, 2010.

JOINT RESEARCH AGREEMENT

The subject matter claimed in this application was made by or on behalfof a joint research agreement between W. R. Grace & Co.-Conn. andExxonMobil Research and Engineering. The aforementioned jointdevelopment agreement was in effect on or before the date the claimedinvention was made, and the claimed invention was made as a result ofactivities undertaken within the scope of the joint research agreement.

FIELD OF THE INVENTION

This invention relates to the composition, method of making and use of afluidized catalytic cracking (“FCC”) catalyst that is comprised of a newY zeolite which exhibits an exceptionally low small mesoporous peakheight around the 40 Å (angstrom) range as determined by nitrogenadsorption measurements and shown in the BJH N₂ Desorption Plot. FCCcatalysts made from this new zeolite exhibit improved rates of heavy oilcracking heavy oil bottoms conversions and gasoline conversions.

BACKGROUND

Conversion of high molecular weight petroleum feeds to more valuableproducts by catalytic processes such as fluidized catalytic cracking isimportant to petroleum processes. In the fluidized catalytic crackingprocess, higher molecular weight feeds are contacted with fluidizedcatalyst particles in the riser reactor of the fluidized catalyticcracking unit. The contacting between feed and catalyst is controlledaccording to the type of product desired. In catalytic cracking of thefeed, reactor conditions such as temperature and catalyst circulationrate are controlled to maximize the products desired and minimize theformation of less desirable products such as light gases and coke.

In the current economics of modern refining, as lighter, easier toconvert feedstocks are in increasingly lesser availabilities and higherpricing, refiners are continually moving to ways in which to process themore challenged or “heavier” feedstocks that are more available and canbe purchased at a discount as compared to the lighter hydrocarbonfeedstocks. These heavier feedstocks tend to have lower API gravities(i.e., denser) and higher viscosities than the lighter hydrocarbonfeedstocks. This makes these heavy oil feedstocks, including gas oilsand vacuum tower bottoms typically fed to an associated fluidizedcatalytic cracking (or “FCC”) unit more difficult to convert to highvalue products such as gasoline, and require a higher “conversion rates”in order to reduce the amount of heavy hydrocarbons products, i.e.,those products with a boiling point above about 430° F. (221° C.),generated from the cracking process and higher yields of gasolineproduct.

With the advance of zeolitic cracking catalysts with greatly improvedcracking activity, most modern fluidized catalytic cracking reactorsutilize a short contact-time cracking configuration. With thisconfiguration, the time in which the catalyst and the fluidizedcatalytic cracker feedstream are in contact is limited in order tominimize the amount of excessive cracking which results in the increasedproduction of less valued products such as light hydrocarbon gases aswell as increased coking deposition on the cracking catalysts. Shortcontact-time riser reactor designs are relatively new to thepetrochemical industry, but have gained wide-spread acceptance and usein the industry due to the ability of optimizing hydrocarbon crackingproducts and yields in conjunction with the use of modern crackingcatalysts.

Conventional FCC catalysts have used type Y zeolites as part of theircomposition. Type “Y” zeolites are of the faujasite (“FAU”) frameworktype which is described in Atlas of Zeolitic Framework Types (Ch.Baerlocher, W. M. Meier, and D. H. Olson editors, 5th Rev. Ed., ElsevierScience B.V., 2001) and in the pure crystalline form are comprised ofthree-dimensional channels of 12-membered rings The crystalline zeoliteY is described in U.S. Pat. No. 3,130,007. Zeolite Y (see U.S. Pat. No.3,130,007) and improved Y-type zeolites such as Ultra Stable Y (“USY” or“US-Y”) (see U.S. Pat. No. 3,375,065) not only provide a desiredframework for shape selective reactions but also exhibit exceptionalstability in the presence of steam at elevated temperatures which hasresulted in this zeolite structure being utilized in many catalyticpetroleum refining and petrochemical processes. Additionally, thethree-dimensional pore channel structure of the faujasite frameworkzeolites, such as the Y-type zeolites, in combination with theirrelatively good ability to retain a high surface area under severehydrothermal conditions and their generally low cost to manufacturemakes these zeolites a preferred component for Fluid Catalytic Cracking(“FCC”) catalysts in petroleum refining and petrochemical processes.

In a pure zeolite crystal, the pore diameters are typically in the rangeof a few angstroms in diameter. Y-type zeolites exhibit pore diametersof about 7.4 Angstroms (Å) in the pure crystal form. However, inmanufacture, defects in the crystalline structure and in particular inthe inter-crystal interfaces occur in the crystalline structure ofzeolites, including the Y-type zeolites. Additionally, due to certainmethods of preparations and/or use, both wanted and unwanted structuralmodifications can be made to the zeolite crystal. It is these “defects”which lead to specific properties of the zeolite which may havebeneficial properties when utilized in catalytic processes. ConventionalUltra Stable Y (USY) zeolites prepared by mild steam calcination, astaught by U.S. Pat. No. 3,375,065, contain significant amounts ofmesopores in the 30 to 50 Å regions. These pores with pore diameters inthe 30 to 50 Å range are herein defined as “Small Mesopores”.

What are needed in the industry are improved catalysts which haveimproved heavy improved heavy oil conversion rates as well as improvedgasoline yields and lower undesired coke production. In particular, whatare needed in the industry are improved fluidized catalytic cracking(“FCC”) catalysts that exhibit these properties. Even more preferablydesired is fluidized catalytic cracking (“FCC”) catalysts that are easyto manufacture that can be used in existing short contact time FCC unitswith little or no modifications required to the existing unit thatexhibit improved conversions and gasoline production properties.

SUMMARY

This invention includes in part the composition, method of making anduse of a small mesoporous peak fluidized catalytic cracking (“FCC”)catalyst that is comprised of a new Y zeolite which exhibits anexceptionally low small mesoporous peak height around the 40 (angstrom)range as measured by nitrogen adsorption and shown in the BJH N₂Desorption Plot. FCC catalysts made from this new zeolite, and asdescribed herein, exhibit improved rates of heavy oil cracking heavy oilbottoms conversions and gasoline conversions. The present inventionincludes the composition, method of making and use of fluidizedcatalytic cracking catalysts incorporating an extra mesoporous Y zeolite(termed herein as “EMY” zeolite) which has improved mesoporousproperties over Y zeolites of the prior art, as well as a method ofmaking the zeolite and its use in fluidized catalytic cracking process.This zeolite is described herein as well as described further in U.S.Ser. No. 12/584,376 entitled “Extra Mesoporous Y Zeolite”, which isincorporated in its entirety herein.

An embodiment of the present invention is a fluidized catalytic crackingcatalyst comprised of:

-   -   a Y zeolite with a Large Mesopore Volume of at least about 0.03        cm³/g and a Small Mesopore Peak of less than about 0.15 cm³/g;        and    -   an inorganic matrix.

In a preferred embodiment of the fluidized catalytic cracking catalystof the present invention, the zeolite has a Large-to-Small Pore VolumeRatio of at least about 4.0. In yet another preferred embodiment, theunit cell size of the zeolite is less than about 24.45 Angstroms. Inanother preferred embodiment, the inorganic matrix is comprised ofoxides of silicon, aluminum or combinations thereof. In a most preferredembodiment of the fluidized catalytic cracking catalyst of the presentinvention, the inorganic matrix is comprised of a peptized alumina.Preferably, the fluidized catalytic cracking catalyst is furthercomprised of a clay.

In yet another most preferred embodiment of the fluidized catalyticcracking catalyst of the present invention, the fluidized catalyticcracking catalyst has a 40 Å Peak of less than about 0.13 cm³/g.

An embodiment of the present invention is a method of making a low smallmesopore peak fluidized catalytic cracking catalyst, comprising thesteps of:

-   -   a) combining a binder precursor selected from a silica, an        alumina, or a combination thereof, with a clay and a zeolite to        form a catalyst mixture; and    -   b) drying the catalyst mixture to form a catalyst; wherein the        zeolite is a Y zeolite with a Large Mesopore Volume of at least        about 0.03 cm³/g and a Small Mesopore Peak of less than about        0.15 cm³/g.

In a preferred embodiment of the method of making the fluidizedcatalytic cracking catalyst, the binder precursor is selected from acolloidal silica, silica gel, a silica sol, or a combination thereof. Inyet another preferred method of making, the binder precursor is selectedfrom a colloidal alumina, alumina gel, a silica sol, or a combinationthereof. Preferably, the binder precursor is comprised of peptizedalumina. In another preferred method of making, the catalyst mixturecomprises an alumina and a silica. In yet another preferred embodimentof the method of making the fluidized catalytic cracking catalyst of thepresent invention, the clay is selected from kaolin, bentonite, andcombinations thereof.

In another embodiment of the present invention is a fluidized catalyticcracking (or “FCC”) process for catalytically cracking a hydrocarbonfeedstock, comprising:

-   -   a) contacting the hydrocarbon feedstock with a fluidized        catalytic cracking catalyst comprised of a Y zeolite with a        Large Mesopore Volume of at least about 0.03 cm³/g and a Small        Mesopore Peak of less than about 0.15 cm³/g; and an inorganic        matrix; and    -   b) producing at least one product stream which has a lower        average molecular weight than the hydrocarbon feedstock;    -   wherein the zeolite has a Large Mesopore Volume of at least        about 0.03 cm³/g, and a Small Mesopore Peak of less than about        0.15 cm³/g.

In another preferred embodiment, the petroleum refining process isperformed at hydrocarbon cracking catalyst at cracking conditionscomprising temperatures from about 1000° F. to about 1500° F. (538° C.to 816° C.); catalyst to feed (wt/wt) ratios from about 2 to 10; andriser reaction zone catalyst/hydrocarbon contact durations of less thanabout 5 seconds.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a BJH N₂ Desorption Plot of a USY zeolite from a commerciallyavailable ammonium-Y zeolite (prior art).

FIG. 2 is a BJH N₂ Desorption Plot of the USY zeolite of FIG. 1 (priorart) after it has been subjected to ion exchange/calcination steps andlong-term deactivation steaming at 1400° F. for 16 hours.

FIG. 3 is a BJH N₂ Desorption Plot of an embodiment of an ExtraMesoporous Y)(“EMY”) zeolite as utilized in the catalysts of the presentinvention.

FIG. 4 is a BJH N₂ Desorption Plot of an embodiment of an ExtraMesoporous Y (“EMY”) zeolite after it has been subjected toion-exchange/calcination steps and long-term deactivation steaming at1400° F. for 16 hours.

FIG. 5 shows the catalyst property data associated with the LS-USY,LS-EMY, ULS-USY, and ULS-EMY SiO₂ matrix catalysts samples of Example 3.

FIGS. 6A and 6B are graphs comparing the process test data from theLS-USY and LS-EMY catalyst sample testing of Example 4.

FIGS. 7A and 7B are graphs comparing the process test data from theULS-USY and ULS-EMY catalyst sample testing of Example 4.

FIG. 8 is an overlay of BJH N₂ Desorption Plots for the USY and EMYAl₂O₃ matrix catalysts of Example 5.

FIG. 9 is a table of the process test data from the USY and EMY Al₂O₃matrix catalyst sample testing of Example 6.

FIGS. 10A and 10B are graphs comparing the process test data from theUSY and EMY Al₂O₃ matrix catalyst sample testing of Example 6.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The fluidized catalytic cracking (“FCC”) catalyst of the presentinvention incorporates the use of an Extra Mesoporous Y (“EMY”) zeoliteand its use in hydrocarbon cracking catalysts. This zeolite is describedherein as well as described further in U.S. Ser. No. 12/584,376 entitled“Extra Mesoporous Y Zeolite”, which is incorporated in its entiretyherein. The catalysts herein comprising this new zeolite have beenunexpectedly found to have improved hydrocarbon conversions, includingimproved gasoline yields, particularly when utilized in a fluidizedcatalytic cracking (“FCC”) process of the present invention.

In the fluidized catalytic cracking catalysts of the present inventionis utilized what is termed herein as an EMY zeolite which is a newlydeveloped Y-type zeolite with a suppressed “small mesopore peak” that iscommonly found associated within the “small mesopores” (30 to 50 Å porediameters) of commercial Y-type zeolites, while maintaining asubstantial volume of pores in the “large mesopores” (greater than 50 to500 Å pore diameters) of the zeolite. International Union of Pure andApplied Chemistry (“IUPAC”) standards defines “mesopores” as having porediameters greater than 20 to less than 500 Angstroms (Å). However, thestandard nitrogen desorption measurements as used herein do not providepore volume data below about 22 Å. Additionally, since the “smallmesopore peak” found in Y zeolites are substantially confined betweenthe 30 and 50 Å ranges, it is sufficient to define the measurablemesoporous pore diameter range for the purposes of this invention aspore diameters from 30 to 500 Angstroms (Å).

Therefore, as utilized herein, the terms “Small Mesopore(s)” or “SmallMesoporous” are defined as those pore structures in the zeolite crystalwith a pore diameter of 30 to 50 Angstroms (Å). Similarly, the terms“Large Mesopore(s)” or “Large Mesoporous” as utilized herein are definedas those pore structures in the zeolite crystal with a pore diameter ofgreater than 50 to 500 Angstroms (Å). The terms “Mesopore(s)” or“Mesoporous” when utilized herein alone (i.e., not in conjunction with a“small” or “large” adjective) are defined herein as those porestructures in the zeolite crystal with a pore diameter of 30 to 500Angstroms (Å). Unless otherwise noted, the unit of measurement used formesoporous pore diameters herein is in Angstroms (Å).

The term “Small Mesopore Volume” or “Small Mesoporous Volume” of amaterial as used herein is defined as the total pore volume of the poresper unit mass in the Small Mesopore range as measured and calculated byASTM Standard D 4222 “Determination of Nitrogen Adsorption andDesorption Isotherms of Catalysts and Catalyst Carriers by StaticVolumetric Measurements”; ASTM Standard D 4641 “Calculation of Pore SizeDistributions of Catalysts from Nitrogen Desorption Isotherms”; and “TheDetermination of Pore Volume and Area Distributions in PorousSubstances, I. Computations from Nitrogen Isotherms”, by Barrett, E. P.;Joyner, L. S.; and Halenda, P. P.; Journal of American Chemical Society;vol. 73, pp. 373-380 (1951), all of which are incorporated herein byreference. Unless otherwise noted, the unit of measurement for mesoporevolume is in cm³/g.

The term “Large Mesopore Volume” or “Large Mesoporous Volume” of amaterial as used herein is defined as the total pore volume of the poresper unit mass in the Large Mesopore range as measured and calculated byASTM Standard D 4222 “Determination of Nitrogen Adsorption andDesorption Isotherms of Catalysts and Catalyst Carriers by StaticVolumetric Measurements”; ASTM Standard D 4641 “Calculation of Pore SizeDistributions of Catalysts from Nitrogen Desorption Isotherms”; and “TheDetermination of Pore Volume and Area Distributions in PorousSubstances, I. Computations from Nitrogen Isotherms”, by Barrett, E. P.;Joyner, L. S.; and Halenda, P. P.; J. Amer. Chem. Soc.; vol. 73, pp.373-380 (1951). Unless otherwise noted, the unit of measurement formesopore volume is in cm³/g.

The term “Large-to-Small Pore Volume Ratio” or “LSPVR” of a material asused herein is defined as the ratio of the Large Mesopore Volume to theSmall Mesopore Volume (dimensionless).

The term “BJH N₂ Desorption Plot” as used herein is defined as a plot ofthe change in unit volume of a mesoporous material as a function of thepore diameter of the mesoporous material. Herein, the “BJH N₂ DesorptionPlot” is shown as the pore volume calculated as dV/dlogD (in cm³/g) vs.the pore diameter (in nanometers) as determined by the ASTM Standard D4222, ASTM Standard D 4641, and “The Determination of Pore Volume andArea Distributions in Porous Substances, I. Computations from NitrogenIsotherms”, by Barrett, E. P.; Joyner, L. S.; and Halenda, P. P.;Journal of American Chemical Society; vol. 73, pp. 373-380 (1951),(i.e., the “BJH method” for calculating the pore distribution of aporous substance) as referenced in the definitions above. The BJH N₂Desorption Plot should be generated from approximately 15 to 30 datapoints at approximately equidistant positions on a logarithmic x-axis ofthe pore diameter (nanometers) between the values of 3 to 50 nanometers(30 to 500 Å). The pore volume value on the y-axis of the plot iscommonly calculated in industry equipment as an interpolated value ofthe incremental change in volume, dV (where V is in cm³, and dV is incm³) divided by the incremental change in the log of the pore diameter,dlogD (where D is in nanometers, and dlogD is unitless) and is adjustedto the unit weight of the sample in grams. Therefore, the “pore volume”(which is the common term utilized in the industry) as shown on they-axis of the BJH N₂ Desorption Plot may be more appropriately describedas an incremental pore volume per unit mass and is expressed herein inthe units cm³/g. It should be noted that the “pore volume” value on they-axis of the BJH N₂ Desorption Plot is not synonymous with the “SmallMesopore Volume” and “Large Mesopore Volume” as described above whichare calculated unit pore volumes over a range of pore diameters.However, these calculations and terms as used herein are familiar tothose of skill in the art. All measurements and data plots as utilizedherein were made with a Micromeritics® Tristar 3000® analyzer.

The term “Small Mesopore Peak” as used herein refers to the property ofa zeolite and is defined as the maximum pore volume value calculated asdV/dlogD (y-axis) on a BJH N₂ Desorption Plot as described above (porevolume vs. pore diameter) between the 30 Å and 50 Å pore diameter rangex-axis). Unless otherwise noted, the unit of measurement for the smallmesopore peak is in cm³/g.

The term “40 Å Peak” or “40 Å Peak Height” as used herein refers to theproperty of a catalyst and is defined as the maximum pore volume valuecalculated as dV/dlogD (y-axis) on a BJH N₂ Desorption Plot as describedabove (pore volume vs. pore diameter) at 40 Å pore diameter (x-axis).Unless otherwise noted, the unit of measurement for the 40 Å Peak is incm³/g.

The term “Large Mesopore Peak” used herein refers to the property of azeolite and is defined as the maximum pore volume value calculated asdV/dlogD (y-axis) on a BJH N₂ Desorption Plot as described above (porevolume vs. pore diameter) between the 50 Å and 500 Å pore diameter rangex-axis). Unless otherwise noted, the unit of measurement for the largemesopore peak is in cm³/g.

The term “BET Surface Area” for a material as used herein is defined asthe surface area as determined by ASTM Specification D 3663. Unlessotherwise noted, the unit of measurement for surface area is in m²/g.

The term “Unit Cell Size” for a material as used herein is defined asthe unit cell size as determined by ASTM Specification D 3942. Unlessotherwise noted, the unit of measurement used for unit cell size hereinis in Angstroms (Å).

While not wishing to be held to any specific theory, it is believedherein that a problem that exists with the existing Y zeolites in theindustry in that some of these Y-type zeolites (e.g., Na—Y zeolites),while widely used in the industry, exhibit a “peak” in the smallmesopore range (30 to 50 Å pore diameters) while exhibiting nosignificant pore volume associated with the large mesopore range (50 to500 Å pore diameters). Conversely, other Y-type zeolites (e.g., USYzeolites), exhibit a significant “peak” in the small mesopore range (30to 50 Å pore diameters) when some large mesopores are present. It isbelieved and is discovered herein that the pore volume in the smallmesopore range (30 to 50 Å pore diameters) of these zeolite contributesto unwanted adverse conversion effects when utilized in hydrocarboncracking processes.

As discussed, conventional Y zeolites contain a significant volumeassociated with pores in the range of 30 to 50 Å diameter, which areeasily observed by a standard nitrogen adsorption-desorption test asinterpreted by the BJH method. FIG. 1 shows a typical the BJH N₂Desorption Plot of a typical USY zeolite. As can be seen in FIG. 1, theUSY exhibits a high volume of pores in the “small mesoporous” range (30to 50 Å pore diameter) as well as a significant “small mesopore peak” inthe BJH N₂ Desorption Plot of about 0.20 cm³/g or more in this smallmesopore range. This high peak in the 30 to 50 Å pore diameter range ofthe BJH N₂ Desorption Plot is a common feature for Y-zeolite materialsthat possess a significant pore volume in the mesoporous range (30 to500 Å pore diameters). This peak exhibited in the BJH N₂ Desorption Plotof the Y zeolites is termed herein as the “Small Mesopore Peak” of thezeolite and is defined above. Without wishing to be held to any theory,it is believed that this phenomenon occurs due to a “bottlenecking” ofsome of the mesoporous structures in the zeolite creating an ink-bottleeffect wherein a significant amount of the nitrogen inside the internalpore cavities cannot be released during the desorption phase of the testuntil the partial pressure is reduced below the point associated withthis small mesopore peak point. Typically in a standard nitrogenadsorption/desorption test this peak is associated at a point in thedesorption branch at a relative nitrogen pressure (P/P_(o)) of about 0.4to about 0.45. See “Characterization of Porous Solids and Powders:Surface Area, Pore Size and Density”, by Lowell, S., Shields, J. E.,Thomas, M. A., and Thommes, M., pp. 117-123, (Springer, Netherlands2006), which is incorporated herein by reference.

As can further be seen in FIG. 1, there is no significant “largemesopore peak” associated with the large mesoporous structure (50 to 500Åpore diameter range) of the USY zeolite, The USY sample of this exampleis further described in Example 1. While USY zeolites do not possess asignificant volume of large mesopores (in the 50 and 500 Å diameterrange) upon fabrication, they may develop these large mesopores uponsteaming at high temperatures. A common test in the industry is tocontact the zeolite with a high temperature steam (for example, 100%partial pressure steam at 1400 for 16 hours) to determine thehydrothermal stability of the zeolite. This test is designed to simulatethe steaming conditions of a FCC unit wherein the catalysts aretypically exposed to steam at elevated temperatures to representconditions under which the FCC catalysts will be commercially exposed.The main reason for this test is to determine the ability of the zeoliteto retain surface area when exposed to steam at high temperatures.However, upon severe steaming, Y-type zeolites also tend to increase thepore volume associated with the large mesopores, and the surface area ofthe zeolite tends to diminish as the steaming conditions become moresevere.

According to the details of Example 1, a conventional USY sample asdescribed above and shown in FIG. 1 was further ammonium ion-exchangedthree times and then steamed at 1400° F. for 16 hours to determine theresulting pore distribution and surface area stability of the USYzeolite under these hydrothermal conditions. FIG. 2 shows the BJH N₂Desorption Plot of the ion-exchanged USY zeolite after long-termdeactivation steaming. As can be seen from FIG. 2, the steamed USYdevelops a “large mesopore peak” in the large mesoporous structures (50to 500 Å pore diameter range) of the zeolite. However, as also can beseen in FIG. 2, the “small mesopore peak”, associated with pores in the30 to 50 Å pore diameter range of the steamed USY, is not significantlydecreased as compared to the small mesopore peak of the un-steamed USYsample as shown in FIG. 1. Here, the small mesopore peak of the steamedUSY is about 0.19 cm³/g.

While not wishing to be held to any theory, it is believed that thesmall and large mesoporous pore structures of the zeolite are created bydefects and/or deterioration of the zeolite crystalline structure,thereby creating structural defect voids (or equivalent “pores”) thatare larger in size than those of the as-synthesized (pure crystal)structure of the zeolite.

The fluidized catalytic cracking catalysts of the present inventionutilize a highly hydrothermally stable Y-zeolite that has asignificantly suppressed small mesopore peak in both the as-fabricatedand as-steamed conditions while maintaining a high volume of largemesopores (50 to 500 Åpore diameter range). In another embodiment of thepresent invention, is a catalyst comprised of a highly hydrothermallystable Y-zeolite that has a significantly suppressed small mesopore peakin both the as-fabricated and as steamed conditions while maintaining ahigh ratio of large-to-small mesoporous volume. The zeolite utilized inthe catalysts of this invention is termed herein as “Extra Mesoporous Y”(or “EMY”) zeolite.

In an embodiment of the fluidized catalytic cracking catalysts of thepresent invention, is utilized an EMY zeolite, which can be obtainedfrom a starting material of a conventional Na—Y type zeolite with asodium oxide (Na₂O) content of about 10 to 15 wt %. In an embodiment ofthe present invention, the EMY zeolite precursor is ammonium-exchangedto lower the Na₂O content to a desired level for the production of anEMY zeolite. Generally, about one to about three ammonium-exchanges arerequired to reduce the Na₂O content of a typical Na—Y precursor to adesired level for the production of an EMY zeolite. Based on fabricationtesting, it is believed by the inventor at this time that the sodiumlevel of the EMY precursor must be maintained in certain ranges in orderto obtain an EMY zeolite. In a preferred embodiment of the presentinvention, the Na₂O content of the ammonium-exchanged Na—Y zeoliteprecursor is brought to about 2.0 to about 5.0 wt % Na₂O. Morepreferably, the Na₂O content of the ammonium-exchanged Na—Y zeoliteprecursor is brought to about 2.3 to about 4.0 wt % Na₂O. In thispreferred embodiment, it is believed that the number of ion-exchangesteps performed is not essential to the formation of EMY as long as theNa₂O content of the EMY precursor is within a desired range. Unlessotherwise noted, the Na₂O content is as measured on the zeoliteprecursor prior to high temperature steam calcination and reported on adry basis.

The EMY precursors or the final EMY zeolite may also be rare earthexchanged to obtain a rare earth exchanged EMY or “RE-EMY” zeolite. Thezeolites may be rare earth exchanged in accordance with any ion-exchangeprocedure known in the art. It should also be noted that the weightpercentages used herein are based on the dry weight of the zeolitematerials.

The ammonium-exchanged Na—Y precursor thus obtained is subjected to avery rapid high temperature steam calcination. In this high temperaturesteam calcination process, the temperature of the steam is from about1200 to about 1500° F. More preferably the temperature of the steam isfrom about 1200 to about 1450° F., more preferably from about 1250 toabout 1450° F., and even more preferably from about 1300 to about 1450°F. These high temperature steam calcination temperatures for theproduction of an EMY zeolite are generally higher than those used in theproduction of conventional USY zeolites which are high temperature steamcalcined at temperatures from about 1000 to about 1200° F. and do notundergo the rapid heating in the high temperature calcination step asthe EMY zeolites of the present invention.

It has been discovered that it is important in achieving the EMY zeolitestructure that the zeolite precursor be brought up close to the desiredsteaming temperature in a very rapid manner. The temperature of thezeolite during the steaming process may be measured by a thermocoupleimplanted into the bed of the EMY zeolite precursor.

In a preferred embodiment of making the EMY zeolite, the temperature ofthe zeolite is raised from a standard pre-calcination temperature towithin 50° F. (27.8° C.) of the steam temperature during the hightemperature steam calcination step in less than about 5 minutes. In amore preferred embodiment of making the EMY zeolite, the temperature ofthe zeolite is raised from a standard pre-calcination temperature towithin 50° F. (27.8° C.) of the steam temperature during the hightemperature steam calcination step in less than about 2 minutes.Although not critical to the fabrication process and not so limited asto the claimed invention herein, typically the pre-calcinationtemperature in a Y-type zeolite manufacturing process is from about 50°F. to about 300° F.

Example 2 herein describes the synthesis of one embodiment of an ExtraMesoporous Y (“EMY”) zeolite. FIG. 3 shows the BJH N, Desorption Plot ofthe EMY zeolite sample from Example 2 prior to additional ammoniumexchange and long-term deactivation steaming. As can be seen in FIG. 3,the EMY zeolite exhibits a very low volume of pores in the “smallmesoporous” range (30 to 50 Å pore diameter) as well as a very low“small mesopore peak” of about 0.09 cm³/g in this small mesopore range.In comparing FIG. 1 (USY zeolite) and FIG. 3 (EMY zeolite) it should benoted that this “small mesopore peak” has been substantially depressedin the EMY zeolite. It can be seen in FIG. 1 that this small mesoporepeak is about 0.20 cm³/g for the USY as compared to the small mesoporepeak of about 0.09 cm³/g for the EMY as shown in FIG. 3.

As can further be seen in FIG. 3, there is beneficially a significant“large mesopore peak” associated mainly with the large mesoporousstructures (50 to 500 Å pore diameter range) of the EMY zeolite.Comparing this to the BJH N₂ Desorption Plot of the USY zeolite in FIG.1, it can be seen that the EMY zeolite in FIG. 3 exhibits a significantlarge mesopore peak of about 0.19 cm³/g whereas the USY zeolite in FIG.1 shows no significantly comparable large mesopore peak in this range.

The pore volumes in each of the ranges, 30 to 50 Angstroms as well as 50to 500 Angstroms were determined by utilizing the pore volume data fromthe BJH N₂ Desorption tests and interpolating the data to the necessaryendpoints. This method for calculating the pore volumes is explained indetail in Example 1 and the same method for calculating the pore volumeswas utilized throughout all examples herein. The method as describedtherein defines how to interpret and calculate the pore volume values ofthe zeolites within each of the defined pore diameter ranges.

The “small mesopore” and “large mesopore” pore volumes and the BETsurface areas for the USY and EMY zeolites of FIGS. 1 and 3,respectively, were measured and are shown in Table 1 as follows:

TABLE 1 Zeolite Properties prior to Long-Term Steaming Small (30- Large(50- Large- Small 50 Å) 500 Å) to-Small Mesopore BET Unit MesoporeMesopore Pore Peak, Surface Cell Volume Volume Volume dV/dlogD Area SizeZeolite (cm³/g) (cm³/g) Ratio (cm³/g) (m²/g) (Å) USY 0.0193 0.0195 1.010.20 811 24.55 (FIG. 1) EMY 0.0109 0.0740 6.79 0.09 619 24.42 (FIG. 3)

It should be noted that FIGS. 1 and 3, as well as the data in Table 1,reflect the USY and EMY zeolite samples after the high temperature steamcalcination step and prior to any subsequent treating. As can be seen inTable 1, the volume of small mesopores is larger in the USY zeolite thanin the EMY zeolite. However, it can also be seen that the volume oflarge mesopores in the EMY zeolite is significantly larger than thevolume of large mesopores in the USY zeolite. As discussed, it isdesired to lower the amount of pore volume in the small mesopore rangeand increase the amount of pore volume in the large mesopore range ofthe zeolite. Therefore, an important characteristic of the zeolite isthe ratio of the large mesopore volume (“LMV”) to the small mesoporevolume (“SMV”) of the subject zeolite. We term this ratio of the LMV:SMVas the “Large-to-Small Pore Volume Ratio” or “LSPVR” of the zeolite.

As can be seen from Table 1, the Large-to-Small Pore Volume Ratio or“LSPVR” of the sample USY zeolite is about 1.01 wherein the LSPVR of thesample EMY zeolite is about 6.79. This is a significant shift in theLarge-to-Small Pore Volume Ratio obtained by the present invention. In apreferred embodiment, the LSPVR of the EMY is at least about 4.0, morepreferably at least about 5.0, and even more preferably, the LSPVR ofthe EMY is at least about 6.0 immediately after the first hightemperature steam calcination step as described herein.

Additionally, the EMY zeolites of the present invention may be used inprocesses that are not subject to exposure to high temperaturehydrothermal conditions. It can be seen from Table 1, that one of theremarkable aspects of the EMY zeolites of the present invention is thatthey exhibit very high Large Mesopore Volumes as compared to thecomparable USY of the prior art. This characteristic of the EMY zeolitesof the present invention can be valuable to many commercial processes.In preferred embodiments, the as-fabricated EMY zeolites of the presentinvention have a Large Mesopore Volume of at least 0.03 cm³/g, morepreferably at least 0.05 cm³/g, and even more preferably at least 0.07cm³/g.

As utilized herein, the term “as-fabricated” or “as-fabricated zeolite”of the present invention is defined as the zeolite and its properties asobtained directly after the high temperature steam calcination step(i.e., when the EMY zeolite is formed). As one of skill in the art willbe aware, subsequent additional steps (e.g., further ion-exchange) canbe performed on the zeolite after forming what is considered the EMYzeolite herein. Unless otherwise stated herein or in the claims, thezeolite properties are measured and defined herein as of this“as-fabricated” point in the fabrication process. As is known to one ofskill in the art, the “long-term deactivation steaming” referred toherein is generally utilized as a tool to test the ability of theas-fabricated zeolite to withstand hydrothermal conditions and is notconsidered as a part of the fabrication of the zeolite.

It should also be noted that it is obvious to those of skill in the artthat long-term deactivation steaming will tend to increase the LargeMesopore Volume of typical Y zeolites. However, this unusual aspect ofthe EMY zeolites of the present invention of possessing such asignificantly increased Large Mesopore Volume prior to long-termdeactivation steaming can be useful in processes wherein hightemperature hydrothermal conditions are not present or even moreimportantly in processes wherein it is undesired for the fabricatedzeolite to be long-term steam deactivated. The as-fabricated EMY zeolitepossesses higher BET surface areas as compared to the BET surface areasafter the log-term steam deactivation and the as-fabricated EMY zeolitemay be more stable in some applications than that the EMY zeoliteobtained after long-term steam deactivation.

It can also be seen from comparing FIG. 1 (USY zeolite sample) and FIG.3 (EMY zeolite sample) that the small mesopore peak in the 30 to 50 Åpore diameter range is significantly lower for the EMY zeolite than theUSY zeolite. In a preferred embodiment, the as-fabricated EMY zeoliteobtained following the high temperature steam calcination exhibits aSmall Mesopore Peak of less than about 0.15 cm³/g. In a more preferredembodiment, the EMY zeolite has a Small Mesopore Peak of less about 013cm³/g, and in an even more preferred embodiment, the Small Mesopore Peakof the EMY is less than about 0.11 cm³/g. The Small Mesopore Volume Peakas defined prior is the maximum value (or peak) of the pore volume value(dV/dlogD, y-axis) exhibited on the BJH N₂ Desorption Plot in the 30 to50 Angstroms (Å) pore diameter range.

In addition, the EMY materials of the present invention exhibit smallerunit cell sizes as compared to similar USY materials that have undergonea single high temperature steam calcination step. As can be seen inTable 1, the USY zeolite of Example 1 has a unit cell size of about24.55 Å, while the EMY zeolite prepared from similar starting materialshas a significantly lower unit cell size of about 24.42 Å.

It has been discovered that in preferred embodiments, theseas-fabricated EMY zeolites exhibit unit cell sizes that are less than24.45 Å. Preferably, the as-fabricated EMY zeolites exhibit unit cellsizes ranging from about 24.37 to about 24.47 Å after the first hightemperature steam calcination step as described herein. In even morepreferred embodiments, the as-fabricated EMY zeolites have low unitcells size from about 24.40 to about 24.45 Å after the first hightemperature steam calcination step as described herein. This smallerunit cell size generally results in a more stable zeolite configurationdue to the higher framework silica/alumina ratios reflected by the lowerunit cell sizes of EMY zeolite.

The USY zeolite sample as described in Example 1 and shown in the BJH N₂Desorption Plot of FIG. 1 as well as the EMY zeolite sample as describedin Example 2 and shown in the BJH N₂ Desorption Plot of FIG. 3 werefurther ammonium ion-exchanged and then long-term deactivation steamedat 1400° F. for 16 hours to determine the long-term hydrothermalstability of the USY and EMY zeolites.

FIG. 2 shows the BJH N₂ Desorption Plot of the ion-exchanged USY zeoliteof the prior art after long-term deactivation steaming. FIG. 4 shows theBJH N₂ Desorption Plot of the ion-exchanged EMY zeolite of an embodimentof the present invention after long-term deactivation steaming. As canbe seen from FIG. 4, the Large Mesopore Peak of the EMY zeoliteincreased desirably from about 0.19 cm³/g (as shown in FIG. 3) to about0.36 cm³/g (as shown in FIG. 4) after long-term deactivation steaming.Just as desirable, following long-term deactivation steaming of the EMYzeolite, the Small Mesopore Peak of the EMY zeolite was notsignificantly increased. The Small Mesopore Peak of the EMY zeoliteremained essentially constant at about 0.10 cm³/g (as shown in FIGS. 3and 4).

In contrast, in the comparative USY zeolite of the prior art, the SmallMesopore Peak remained undesirably high at about 0.19 cm³/g afterlong-term deactivation steaming (see FIG. 2).

The physical properties of the zeolites obtained after long-termdeactivation steaming in Examples 1 and 2 are tabulated in Table 2below. In Table 2 below, are shown the “Small Mesopore Volumes”, the“Large Mesopore Volumes, the “Large-to-Small Pore Volume Ratios”, andthe Small Mesopore Peaks” for the USY and EMY zeolites illustrated inFIGS. 2 and 4, respectively, as well as the associated BET surface areasand the unit cell sizes as measured following three ammoniumion-exchanges and long-term deactivation steaming at 1400° F. for 16hours.

TABLE 2 Zeolite Properties after Long-Term Deactivation Steaming Small(30- Large (50- Large- Small 50 Å) 500 Å) to-Small Mesopore BET UnitMesopore Mesopore Pore Peak, Surface Cell Volume Volume Volume dV/dlogDArea Size Zeolite (cm³/g) (cm³/g) Ratio (cm³/g) (m²/g) (Å) USY 0.01120.1211 10.85 0.19 565 24.27 (FIG. 2) EMY 0.0077 0.1224 15.97 0.10 58724.27 (FIG. 4)

Another benefit of the EMY zeolites of the present invention is surfacearea stability. As can be seen in Table 2, the BET surface area for thelong-term deactivation steamed EMY zeolite sample was greater than theBET surface area for the USY sample. Additionally, the EMY retained ahigher percentage of the surface area after the three ammonium ionexchanges and long-term deactivation steaming at 1400° F. for 16 hours.Comparing Table 1 and Table 2, the USY retained about 70% of itsoriginal surface area wherein the EMY retained about 95% of its originalsurface area, indicating the superior hydrostability of the EMY zeolitesof the present invention. In preferred embodiments of the presentinvention, the EMY zeolite has BET Surface Area of at least 500 m²/g asmeasured either before long-term deactivation steaming at 1400° F. for16 hours or after long-term deactivation steaming at 1400° F. for 16hours.

In a preferred embodiment, the “Large-to-Small Pore Volume Ratio” (or“LSPVR”) of the EMY is at least about 10.0, more preferably at leastabout 12.0, and even more preferably, the LSPVR of the EMY is at leastabout 15.0 after long-term deactivation steaming at 1400° F. for 16hours.

In the present invention, the EMY zeolite as described is incorporatedinto the cracking catalysts of the present invention and tested underfluidized catalytic cracking (“FCC”) conditions. Comparative FCCcracking catalysts were fabricated from comparable low sodium-USYzeolite catalysts (“LS-USY”) as well ultralow sodium-USY zeolitecatalysts (“ULS-USY”) as of the prior art and embodiments of the lowsodium-EMY zeolite catalysts (“LS-EMY”) and ultralow sodium-EMY zeolitecatalysts (“ULS-EMY”) of the present invention as detailed in Example 3herein. All of these catalysts were made with a matrix comprised of 21wt % silicon oxide (SiO₂), 39 wt % clay, and 40 wt % either USY or EMYzeolite.

The properties of the fresh catalysts and steam-deactivated catalystsfrom Example 3 are shown in the table in FIG. 5 for the LS-USY, LS-EMY,ULS-USY, and ULS-EMY catalysts made. In particular, it should be notedthat while many of the physical properties between the USY and EMYcatalysts do not show significant differences, the EMY catalysts of thepresent invention exhibit a significantly lower “N2 BJH: 40 Å PeakHeights” as compared to the comparable USY catalysts. It is thisdifferentiating feature that is believed to be directly related to theimproved hydrocarbon processing results achieved in the followingexample.

As shown in Example 4, after steam deactivation of the sample catalystsat 1465° F. for 20 hours, two samples of the low sodium-USY zeolitecatalysts (LS-USY″) of the prior art were tested under typical FCCconditions in a pilot plant and the results compared to testing underthe same conditions of a comparable low sodium-EMY zeolite catalyst(LS-EMY) catalyst of the present invention. The test results werenormalized to a constant coke yield of 3 wt % as a standard forcomparison as many units are coke and heat limited.

As can be seen in FIG. 6A and particularly FIG. 6B (which illustratesthe % difference in values between the LS-USY and LS-EMY data in FIG.6A), a higher catalyst-to-oil ratio for LS-EMY than LS-USY is utilizedat constant coke yield. However, this is not an important factor as mostunits have the ability to adjust the catalyst-to-oil ratio in an FCCunit with little impact on overall unit economics. As can be seen inFIG. 6B, except for a slight decrease in overall conversion. All of theother product variables have been improved. There is a substantialbeneficial decrease in both wet gas and bottoms yields, as well as asubstantial beneficial increase in both gasoline and light cycle oil(“LCO”) yields with an LS-EMY catalyst of the present invention ascompared to LS-USY catalysts.

Also as shown in Example 4, after steam deactivation of the samplecatalysts at 1465° F. for 20 hours, two samples of the ultralowsodium-USY zeolite catalysts (“ULS-USY”) of the prior art were testedunder typical FCC conditions in a pilot plant and the results comparedto testing under the same conditions of a comparable ultralow sodium-EMYzeolite catalyst (“ULS-EMY”) catalyst of the present invention. The testresults were also normalized to a constant coke yield of 3 wt %.

As can be seen in FIG. 7A and particularly FIG. 7B (which illustratesthe difference in values between the ULS-EMY relative to the ULS-USYdata in FIG. 7A), similar results/trends were experienced for theULS-EMY than ULS-USY as from the LS-EMY than LS-USY shown in FIGS. 6Aand 6B. Similar trends were experienced in all of themeasured/calculated variables, including a substantial beneficialdecrease in both wet gas and bottoms yields, as well as a substantialbeneficial increase in both gasoline and light cycle oil (“LCO”) yieldswith an ULS-EMY catalyst of the present invention as compared to ULS-USYcatalysts.

In Example 5, comparative FCC cracking catalysts were fabricated fromcomparable USY zeolite catalysts (“USY catalysts”) of the prior art andembodiments of the EMY zeolite catalysts (“EMY catalysts”) of thepresent invention were fabricated with a matrix of a peptized aluminumoxide (Al₂O₃), a rare earth oxide, (RE₂O₃), and clay. All of thesecatalysts were made with a matrix comprised of 30 wt % peptized aluminumoxide (Al₂O₃), 1.7 wt % rare earth oxide, (RE₂O₃), 25 wt % either USY orEMY zeolite, with the balance clay.

The properties of the fresh catalysts and steam-deactivated catalystsfrom Example 5 are shown in the Table 3 for the USY catalysts and EMYcatalysts made.

TABLE 3 Properties of USY & EMY Catalysts from Example 5 CatalystFormulation 25% ULS-USY 25% ULS-EMY 30% Peptized 30% Peptized Al₂O₃Al₂O₃ 1.7% RE₂O₃ 1.7% RE₂O₃ Balance: Clay Balance: Clay Fresh CatalystProperties Na (wt %) 0.10 0.18 BET Surface Area, m²/g 286 251 MatrixSurface Area, m²/g 96 95 Zeolite Surface Area, m²/g 190 156Steam-deactivated Catalyst Properties BET Surface Area, m²/g 189 185Matrix Surface Area, m²/g 74 72 Zeolite Surface Area, m²/g 116 113 N2BJH 40 Å Peak Height 0.32 0.11

Similar to the SiO₂ matrix catalysts of Example 3, it should be notedthat the EMY catalysts of the present invention exhibit a significantlylower “N2 BJH: 40 Å Peak Heights” as compared to the comparable USYcatalysts. An overlay of BJH Nitrogen Desorption Plots for each of theUSY catalyst and the EMY catalyst of Example 5 is shown in FIG. 8. Ascan be seen in FIG. 8 the two desorption plots are very similar exceptfor the obvious and significant difference in the area of the 40 Å peak.Again, it is this differentiating feature that is believed to bedirectly related to the improved hydrocarbon processing results achievedin the following example.

In a preferred embodiment, the EMY catalyst of the present invention hasa 40 Å Peak of less than about 0.15 cm³/g as exhibited on the BJH N₂Desorption Plot. In a more preferred embodiment, the EMY catalyst of thepresent invention has a 40 Å Peak of less than about 0.13 cm³/g, evenmore preferably less than about 0.11 cm³/g, and most preferably lessthan less than about 0.09 cm³/g as exhibited on the BJH N₂ DesorptionPlot, The 40 Å Peak can be measured after fabrication of the freshcatalyst, but is preferably measured following steam deactivation of thecatalyst.

As shown in Example 6, after steam deactivation at 1465° F. for 20 hoursof the sample catalysts of Example 5, a sample of a USY zeolite catalyst(“USY catalyst”) of the prior art was tested under typical FCCconditions in a pilot plant and the results compared to testing underthe same conditions of a comparable EMY zeolite catalyst (“EMYcatalyst”) of the present invention. Similar to Example 4, the testresults obtained in Example 6 were normalized to a constant coke yieldof 3 wt % as a standard for comparison.

In Example 6, three (3) separate runs were made and the results fromeach run are presented in FIG. 9. The arithmetical average of the three(3) runs is presented in FIG. 10A and the difference in values betweenthe EMY Catalyst relative to the USY Catalyst data of FIG. 10A is shownin FIG. 10B. As can be seen in FIGS. 10A and 10B, a highercatalyst-to-oil ratio for LS-EMY than LS-USY is utilized at constantcoke yield. However, as explained prior, this is not an important factoras most units have the ability to adjust the catalyst-to-oil ratio in anFCC unit with little impact on overall unit economics. Additionally, inFIGS. 10A and 10B it can be seen that except for a decrease in lightcycle oil)(“LCO”) yield, all of the other product variables have beenimproved. There is a substantial beneficial decrease in bottoms yieldsand a decrease in wet gas yields associated with the EMY catalyst.Additionally, there is a beneficial increase in both overall conversionas well as gasoline yields with an EMY catalyst of the present inventionas compared to the USY catalyst.

In preferred embodiment of the present invention, the low mesopore peakfluidized catalytic cracking catalysts of the present invention arecomprised of an EMY zeolite and an inorganic oxide matrix component. Theinorganic oxide matrix component should be sufficient to bind thecatalyst components together so that the catalyst product is hard enoughto survive inter-particle and reactor wall collisions. The inorganicoxide matrix can be made from an inorganic oxide sol or gel which isdried to “glue” the catalyst components together. Preferably, theinorganic oxide matrix will be comprised of oxides of silicon, aluminumor combinations thereof, It is also preferred that separate aluminaphases be incorporated into the inorganic oxide matrix. Species ofaluminum oxyhydroxides-γ-alumina, boehmite, diaspore, and transitionalaluminas such as α-alumina, β-alumina, γ-alumina, δ-alumina, ε-alumina,κ-alumina, and ρ-alumina can be employed. Preferably, the aluminaspecies is an aluminum trihydroxide such as gibbsite, bayerite,norstrandite, or doyelite. The matrix material may also containphosphorous or aluminum phosphate.

In another preferred embodiment of the present invention, the lowmesopore peak fluidized catalytic cracking catalyst is further comprisedof a clay. Preferred clays for use in the present invention arerelatively non-porous clays such as kaolin, bentonite, hectorite,sepiolite, and attapulgite. Preferably, the low mesopore peak crackingcatalyst is comprised of a clay selected from kaolin, bentonite, andcombinations thereof.

In another preferred embodiment of the present invention, the lowmesopore peak fluidized catalytic cracking catalyst is further comprisedof a medium-pore zeolite with is incorporated into the inorganic oxidematrix. Medium-pore size molecular sieves that are suitable for useherein include both medium pore zeolites and silicoaluminophosphates(SAPOs). Medium pore zeolites suitable for use in the practice of thepresent invention are described in “Atlas of Zeolite Structure Types”,eds. W. H. Meier and D. H. Olson, Butterworth-Heineman, Third Edition,1992, which is hereby incorporated by reference. The medium-pore sizezeolites generally have an average pore diameter less than about 0.7 nm,typically from about 0.5 to about 0.7 nm and includes for example, MFI,MFS, MEL, MTW, EUO, MIT, HEU, FER, and TON structure type zeolites(IUPAC Commission of Zeolite Nomenclature). Non-limiting examples ofsuch medium-pore size zeolites, include ZSM-5, ZSM-12, ZSM-22, ZSM-23,ZSM-34, ZSM-35, ZSM-38, ZSM-48, ZSM-50, silicalite, and silicalite 2.The most preferred medium pore zeolite used in the present invention isZSM-5, which is described in U.S. Pat. Nos. 3,702,886 and 3,770,614.ZSM-11 is described in U.S. Pat. No. 3,709,979; ZSM-12 in U.S. Pat. No.3,832,449; ZSM-21 and ZSM-38 in U.S. Pat. No. 3,948,758; ZSM-23 in U.S.Pat. No. 4,076,842; and ZSM-35 in U.S. Pat. No. 4,016,245. As mentionedabove SAPOs, such as SAPO-11, SAPO-34, SAPO-41, and SAPO-42, which aredescribed in U.S. Pat. No. 4,440,871 can also be used herein.Non-limiting examples of other medium pore molecular sieves that can beused herein are chromosilicates; gallium silicates; iron silicates;aluminum phosphates (ALPO), such as ALPO-11 described in U.S. Pat. No.4,310,440; titanium aluminosilicates (TASO), such as TASO-45 describedin EP-A No. 229,295; boron silicates, described in U.S. Pat. No.4,254,297; titanium aluminophosphates (TAPO), such as TAPO-11 describedin U.S. Pat. No. 4,500,651; and iron aluminosilicates. All of the abovepatents are incorporated herein by reference.

The present invention also includes a method of making the lowmesoporous peak fluidized catalytic cracking catalysts described herein.A preferred method of making an embodiment of the low mesoporous peakcatalysts herein comprises the steps of mixing a binder precursorselected from a silica, an alumina, or a combination thereof with a clayand a zeolite to form a catalyst mixture; and drying the catalystmixture to form a catalyst; wherein the zeolite is a Y zeolite with aLarge Mesopore Volume of at least about 0.03 cm³/g and a Small MesoporePeak of less than about 0.15 cm³/g (i.e., an embodiment of an EMYzeolite). In preferred embodiment, the binder precursor is a colloidalsilica, silica gel, a silica sol, or a combination thereof. In preferredembodiment, the binder precursor is a colloidal alumina, alumina gel, aalumina sol, or a combination thereof. In another more preferredembodiment, the binder precursor is a peptized alumina. Methods forproducing a peptized alumina as well as a peptized alumina boundcatalyst are illustrated in U.S. Pat. Nos. 4,086,187 and 4,206,085 whichare herein incorporated by reference.

Preferably, the clay is selected from kaolin, bentonite, andcombinations thereof. Most preferred embodiments of the low mesoporouspeak catalysts and method of making the low mesoporous peak catalysts ofthe present invention include combinations of some or all of the mostpreferred embodiments of the EMY zeolites and catalysts describedherein.

In a preferred embodiment, of the catalysts and method of making thecatalysts invention, include a rare earth element in the catalystbinder/mixture. The rare earth content of the catalyst is typicallymeasured as an oxide. In other preferred embodiments of the method ofmaking the low mesoporous peak catalysts, the catalyst mixture is milledprior to the catalysts drying step. In other preferred embodiments, thecatalyst is formed by spray drying the catalyst mixture at a temperaturefrom about 300° F. to about 650° F. Preferably, the final catalyst hasan average particle size from about 20 microns to about 150 microns.

In a preferred embodiment of the present invention, is a fluidizedcatalytic cracking process for catalytically cracking a hydrocarbonfeedstock using the catalysts of this invention. Preferably, thehydrocarbon feedstock is comprised substantially of hydrocarbons boilingin the range of from about 450 to about 1050° F. By “substantially” asused in the prior sentence, it is meant that at least 80 wt % of thehydrocarbon feedstock boils in the range of from about 450 to about1050° F. Even more preferably, at least 90 wt % of the hydrocarbonfeedstock boils in the range of from about 450 to about 1050° F.

As demand for crude supplies and feedstocks to petroleum refineries andpetrochemical plants has increased, there has been a greater incentiveto process heavier, higher molecular weight feedstreams in many of theassociated separation and conversion units. In particular, as theoverall feed compositions trend toward heavier molecular weighthydrocarbon feedstreams, it continues to become more desirable tocatalytically crack these heavier feeds (also termed “bottoms cracking”)to convert more of these components into high value liquid products. Ina preferred embodiment of the present invention, the hydrocarbonfeedstock is comprised of a gas oil stream, a vacuum bottoms stream, ora combination thereof.

In the FCC process, the hydrocarbon feedstock is conducted to a shortcontact-time FCC reactor. The hydrocarbon feedstock is injected throughone or more feed nozzles into a reactor riser. Within this reactorriser, the hydrocarbon feedstock is contacted with a catalytic crackingcatalyst of the present invention under cracking conditions therebyresulting in spent catalyst particles containing carbon depositedthereon and a lower boiling product stream. In more preferredembodiments of the process, the cracking conditions include:temperatures from about 1000° F. to about 1500° F. (538° C. to 816° C.),preferably about 1150° F. to about 1400° F. (621° C. to about 760° C.);hydrocarbon partial pressures from about 10 to 50 psia (70−345 kPa),preferably from about 20 to 40 psia (140−275 kPa); and a catalyst tofeed (wt/wt) ratio from about 2 to 10, preferably 3 to 8, morepreferably about 5 to 6, where the catalyst weight is total weight ofthe catalyst composite. Steam may be concurrently introduced with thefeed into the reaction zone. The steam may comprise up to about 5 wt %of the feed. Preferably, the FCC feed residence time in the reactionzone is less than about 5 seconds, more preferably from about 3 to 5seconds, and even more preferably from about 2 to 3 seconds.

In the fluidized catalytic cracking process herein, the hydrocarbonfeedstock is catalytically cracked into lighter fuel products, inparticular gasolines, naphthas, and distillates (or “light cycle oils”).

The fluidized catalytic cracking catalyst herein may also be useful inother hydrocarbon catalytic conversion processes such as a hydrocrackingprocess, a hydrodesulfurization process, a reforming process, analkylation process, an oligomerization process, a dewaxing process, oran isomerization process.

Although the present invention has been described in terms of specificembodiments, it is not so limited. All suitable combinations andsub-combinations of preferred characteristics of the catalysts presentedherein are contemplated by the present invention. Suitable alterationsand modifications for operation under specific conditions will beapparent to those skilled in the art. It is therefore intended that thefollowing claims be interpreted as covering all such alterations andmodifications as fall within the true spirit and scope of the invention.

The Examples below are provided to illustrate the manner in which theEMY zeolites of the current invention were synthesized and illustratethe improved product qualities and the benefits from specificembodiments of the current invention thus obtained. These Examples onlyillustrate specific embodiments of the present invention and are notmeant to limit the scope of the current invention.

EXAMPLES Example 1

A commercial ammonium-exchanged Y zeolite with a low sodium content(CBV-300® from Zeolyst™, SiO₂/Al₂O₃ molar ratio=5.3, Na₂O 3.15 wt % ondry basis) was steamed in a horizontal calcination oven which was at atemperature of 100° F. and in a flow of 50% steam+50% N₂ for 1 hour. Theresulting product was an ultra-stable Y (USY) zeolite, and was analyzedwith a Micromeritics® Tristar 3000® analyzer to determine the pore sizedistribution characteristics by nitrogen adsorption/desorption at 77.35°K. The BJH method as described in the specification was applied to theN₂ adsorption/desorption isotherms to obtain the pore size distributionof the zeolite, and a plot of dV/dlogD vs. Average Pore Diameter isshown in FIG. 1.

A copy of the pertinent data generated by the BJH method generated fromthe N₂ adsorption/desorption isotherms for this zeolite sample isreproduced in Table 4 below. This test method and the associated formatof data generated as presented are familiar to one of skill in the art.

TABLE 4 BJH Pore Volume Distribution of USY Sample Pore IncrementalDiameter Average dV/dlogD Cumulative Pore Range Diameter Pore VolumePore Volume Volume (nm) (nm) (nm) (cm³/g) (cm³/g) 312.8-104.1 124.10.010 0.0048 0.0048 104.1-62.8  73.6 0.017 0.0085 0.0037 62.8-41-5 47.80.018 0.0117 0.0032 41.5-30.4 34.1 0.018 0.0142 0.0024 30.4-22.9 25.50.017 0.0162 0.0020 22.9-18.6 20.3 0.015 0.0175 0.0014 18.6-16.8 17.60.016 0.0182 0.0007 16.8-15.0 15.8 0.014 0.0189 0.0007 15.0-13.2 140.0152 0.0198 0.0008 13.2-11.7 12.4 0.0151 0.0206 0.0008 11.7-10.6 11.10.014 0.0212 0.0006 10.6-9.3  9.8 0.014 0.0220 0.0008 9.3-8.2 8.6 0.0160.0229 0.0009 8.2-7.1 7.5 0.019 0.0241 0.0012 7.1-6.1 6.5 0.027 0.02590.0019 6.1-5.3 5.6 0.044 0.0286 0.0027 5.3-4.6 4.9 0.055 0.0317 0.00314.6-4.1 4.4 0.054 0.0344 0.0027 4.1-3.7 3.9 0.203 0.0443 0.0099 3.7-3.33.5 0.075 0.0476 0.0033 3.3-2.9 3.1 0.036 0.0497 0.0022 2.9-2.6 2.80.044 0.0517 0.0019 2.6-2.5 2.5 0.049 0.0531 0.0014 2.5-2.2 2.3 0.0620.0558 0.0028

As can be seen in Table 4, a calculated Cumulative Pore Volume (cm³/g)is associated with a range of Pore Diameter (nm) as the testincrementally desorbs the nitrogen from the test sample. An IncrementalPore Volume is then calculated for each of these ranges. A pore volumewithin a certain range (for example a range from 50 to 500 Å, which isequivalent to 5 to 50 nm as presented in Table 4) can be calculated bysubtracting the Cumulative Pore Volume at 50 nm from the Cumulative PoreVolume at 5 nm. Where necessary, the Cumulative Pore Volume at aspecific pore size can be calculated by interpolating the data withinthe range. This method was utilized for all of the Examples herein.

For example, to determine the total pore volume associated with porediameters between 5 nm and 50 nm, first the Cumulative Pore Volumeassociated with 50 nm was calculated by interpolating the amount of theIncremental Pore Volume (highlighted) associated with the differencebetween 62.8 nm and 50.0 nm in the 62.8 to 41.5 nm pore diameter rangeas shown in the table (highlighted) and adding this amount to theCumulative Pore Volume (highlighted) from the prior range. Thecalculation for the Cumulative Pore Volume associated with 50 nm porediameter was calculated from the data in Table 4 above as follows:

((62.8−50.0)/(62.8−41.5)*0.0032)+0.0085=0.0104 cm³/g

The calculation is then performed similarly for the Cumulative PoreVolume associated with 5 nm pore diameter. The calculation was asfollows:

((5.3−5.0)/(5.3−4.6)*0.0031)+0.0286=0.0299 cm³/g

The total Pore Volume associated with the pore diameter ranges of 5 nmto 50 nm (50 Å to 500 Å) of the USY of this example is thus equal to thedifference in the Cumulative Pore Volumes associated with 5 nm and 50 nmrespectfully as follows:

0.0299 cm³/g−0.0104 cm³/g=0.0195 cm³/g

This value is the Large Mesopore Volume for this USY sample as shown inTable 1. All other pore volumes associated with specific pore diameterranges can be and were calculated herein by the same basic method.

As such, the following properties of this USY zeolite were obtained fromthe data:

Small Mesoporous Volume (Range: 3.0 nm to 5.0 nm): 0.0193 cm³/g

Large Mesoporous Volume (Range: 5.0 nm to 50.0 nm): 0.0195 cm³/g

Ratio of (Large Mesopore Volume)/(Small Mesopore Volume): 1.01

Small Mesopore Peak (dV/dlogD@3.9 nm): 0.20 cm³/g

Additionally, the USY zeolite sample exhibited a BET surface area of 811m²/g, and a unit cell size of 24.55 angstroms.

A sample of the prepared USY zeolite above was further subjected to anammonium ion-exchange consisting of adding 80 grams of the zeolite into800 ml of NH₄NO₃ (1M) solution at 70° C. and agitating for 1 hour,followed by filtration on a funnel and washing the filter cake with 1000ml of de-ionized water. The water rinsed zeolite cake was dried on thefunnel by pulling air through, then in an oven at 120° C. in air forover 2 hours, Chemical analysis of the dried zeolite by ICP showed 0.48wt % Na₂O (dry basis). A Na₂O content of about 0.50 wt % was targeted.The dried zeolite was subjected to long-term deactivation steaming at1400° F. for 16 hours, 100% steam, to determine its hydrothermalstability.

The zeolite obtained after long-term deactivation steaming was similarlyanalyzed in a Micromeritics® Tristar 3000® analyzer. The BJH method wasapplied to the N₂ adsorption/desorption isotherms to obtain the poresize distribution of the zeolite, and a plot of dV/dlogD vs. AveragePore Diameter is shown in FIG. 2. The following properties of thislong-term deactivation steamed USY zeolite were obtained from the data:

Small Mesoporous Volume (Range: 3.0 nm to 5.0 nm): 0.0112 cm³/g

Large Mesoporous Volume (Range: 5.0 nm to 50.0 nm): 0.1211 cm³/g

Ratio of (Large Mesopore Volume)/(Small Mesopore Volume): 10.85

Small Mesopore Peak (dV/dlogD@3.9 nm): 0.19 cm³/g

Additionally, the USY zeolite after long-term deactivation steamingexhibited a BET surface area of 565 m²/g, and a unit cell size of 24.27angstroms.

Example 2

In this example, an embodiment of the Extra Mesoporous Y (“EMY”) zeolitewas prepared as follows:

The same commercial ammonium-exchanged Y zeolite (CBV-300®) with a lowsodium content (SiO₂/Al₂O₃ molar ratio 5.3, Na₂O 3.15 wt % on dry basis)as in Example 1 was placed in a horizontal quartz tube, which wasinserted into a horizontal oven pre-equilibrated at 1400° F. in 100%steam at atmospheric pressure. Utilizing this procedure, the temperatureof the zeolite precursor was raised to within 50° F. of the hightemperature steam calcination temperature (i.e., to 1350° F.) within 5minutes. The steam was let to pass through the zeolite powders. After 1hour, the tube was removed from the horizontal oven and resulting EMYzeolite powders were collected. It should be noted that the startingmaterial (i.e., the EMY precursor zeolite) selected was a low sodiumcontent Y zeolite. As described in the specification above, it isbelieved that production of the EMY zeolite is dependent upon the properzeolite sodium content prior to high temperature steam calcination. Ifthe sodium content is not within the specifications as described herein,the starting Y zeolite may first require ammonium-exchange or methods asknown in the art to reduce the sodium content of the EMY zeoliteprecursor to acceptable levels prior to high temperature steamcalcination to produce the EMY zeolite.

The resulting EMY zeolite was analyzed by a Micromeritics® Tristar 3000®analyzer as used in Example 1. The BJH method as described in thespecification was applied to the N₂ adsorption/desorption isotherms toobtain the pore size distribution of the zeolite, and a plot of dV/dlogDvs. Average Pore Diameter is shown in FIG. 3. The following propertiesof this EMY zeolite were obtained:

Small Mesoporous Volume (Range: 3.0 nm to 5.0 nm): 0.0109 cm³/g

Large Mesoporous Volume (Range: 5.0 nm to 50.0 nm): 0.0740 cm³/g

Ratio of (Large Mesopore Volume)/(Small Mesopore Volume): 6.79

Small Mesopore Peak (dV/dlogD@3.9 nm): 0.09 cm³/g

Additionally, the EMY zeolite sample exhibited a BET surface area of 619m²/g, and a unit cell size of 24.42 angstroms.

A sample of the EMY zeolite above was further subjected to an ammoniumion exchange consisting of adding 100 gams of the EMY zeolite into 1000ml of NH₄NO₃ (1M) solution at 70° C. and agitating for 1 hour, followedby filtration on a funnel and washing the filter cake with 1000 ml ofde-ionized water, The water rinsed zeolite cake was dried on the funnelby pulling air through, then in an oven at 120° C., in air for over 2hours. The ammonium ion exchange was repeated using 60 g of the washedEMY zeolite in 600 ml of NH₄NO₃ (1M) solution at 70° C. and agitatingfor 1 hour, followed by filtration on a funnel and washing the filtercake with 1000 ml of de-ionized water. The water rinsed zeolite cake wasdried on the funnel by pulling air through, then in an oven at 120° C.in air for over 2 hours. Chemical analysis of the dried zeolite by ICPshowed 0.64 wt % Na₂O (dry basis). A Na₂O content of about 0.50 wt % wastargeted. This zeolite was then subjected to long-term deactivationsteaming at 1400° F. for 16 hours, 100% steam, to determine itshydrothermal stability.

The EMY zeolite obtained after long-term deactivation steaming was alsoanalyzed by a Micromeritics® Tristar 3000® analyzer. The BJH method wasapplied to the N₂ adsorption/desorption isotherms to obtain the poresize distribution of the zeolite, and a plot of dV/dlogD vs. AveragePore Diameter is shown in FIG. 4. The following properties of the EMYzeolite after long-term deactivation steaming were thus obtained fromthe data:

Small Mesoporous Volume (Range: 3.0 nm to 5.0 nm): 0.0077 cm³/g

Large Mesoporous Volume (Range: 5.0 nm to 50.0 nm): 0.1224 cm³/g

Ratio of (Large Mesopore Volume)/(Small Mesopore Volume): 15.97

Small Mesopore Peak (dV/dlogD@3.9 nm): 0.10 cm³/g

Additionally, the surface area of the EMY zeolite after long-termdeactivation steaming was analyzed by a BET Test. The zeolite exhibiteda BET surface area of 587 m²/g, and a unit cell size of 24.27 angstroms.

Example 3

In this example, catalyst samples of FCC cracking catalysts werefabricated from comparable low sodium-USY zeolite catalysts (“LS-USY”)well ultralow sodium-USY zeolite catalysts (“ULS-USY”) as of the priorart and embodiments of the low sodium-EMY zeolite catalysts (LS-EMY) andultralow sodium-EMY zeolite catalysts (“ULS-EMY”) of the presentinvention as detailed in Example 3 herein. All of these catalysts weremade with a matrix comprised of 21 wt % silicon oxide (SiO₂), 39 wtclay, and 40 wt % either USY or EMY zeolite.

The catalysts of this example were fabricated as follows:

LS-EMY catalyst: 522.9 g of LS-EMY zeolite (91.8% solid) was mixed in1618 g of deionized water, 546.7 g of Hydrite® (kaolin) clay (85.6%solid), and 741.2 g of Nalco-1034A® (colloidal silica) (34.0% solid),and mixed well, then milled to reduce the solid particle sizes. Themixture was spray dried in a catalyst spray dryer with a two-fluidnozzle and an outlet temperature of 300° F. The spray dried solid wascalcined at 550° C. for 2 hours in air. The calcined solid was screenedusing 120-mesh and 325-mesh screens to obtain the fraction with particlesizes between about 44 and about 125 microns.

ULS-EMY catalyst: 511.3 g of ULS-EMY zeolite (94.0% solid) was mixed in1629 g of deionized water, 546.7 g of Hydrite® (kaolin) clay (85.6%solid), and 741.2 g of Nalco-1034A® (colloidal silica) (34.0% solid),and mixed well, then milled to reduce the solid particle sizes. Themixture was spray dried in a catalyst spray dryer with a two-fluidnozzle and an outlet temperature of 300° F. The spray dried solid wascalcined at 550° C. for 2 hours in air. The calcined solid was screenedusing 120-mesh and 325-mesh screens to obtain the fraction with particlesizes between about 44 and about 125 microns.

LS-USY catalyst: 547.3 g of LS-USY zeolite (87.7% solid) was mixed in1593 g of deionized water, 546.7 g of Hydrite® (kaolin) clay (85.6%solid), and 741.2 g of Nalco-1034A® (colloidal silica) (34.0% solid),and mixed well, then milled to reduce the solid particle sizes. Themixture was spray dried in a catalyst spray dryer with a two-fluidnozzle and an outlet temperature of 300° F. The spray dried solid wascalcined at 550° C. for 2 hours in air. The calcined solid was screenedusing 120-mesh and 325-mesh screens to obtain the fraction with particlesizes between about 44 and about 125 microns.

ULS-USY catalyst: 5383 g of ULS-USY zeolite (89.1% solid) was mixed in1602 g of deionized water, 546.7 g of Hydrite® (kaolin) clay (85.6%solid), and 741.2 g of Nalco-1034A® (colloidal silica) (34.0% solid),and mixed well, then milled to reduce the solid particle sizes. Themixture was spray dried in a catalyst spray dryer with a two-fluidnozzle and an outlet temperature of 300° F. The spray dried solid wascalcined at 550° C. for 2 hours in air. The calcined solid was screenedusing 120-mesh and 325-mesh screens to obtain the fraction with particlesizes between about 44 and about 125 microns.

The finished catalysts were steam deactivated at approximately 1465° F.for 20 hours. The properties of the fresh catalysts andsteam-deactivated catalysts fabricated in this Example are shown in thetable in FIG. 5 for the LS-USY, LS-EMY, ULS-USY, and ULS-EMY catalystsmade.

Example 4

In this example, the catalyst samples from Example 3 were tested in alaboratory scale ACE unit under conditions simulating fluidizedcatalytic cracking (“FCC”) process conditions. An ACE (or “AdvancedCracking Evaluation”) unit is a commercially available laboratory scalefluidized bed catalytic cracking unit commonly used in the industry forevaluating catalytic cracking catalysts, feedstocks, and processconditions. After steam deactivation of the sample catalysts at 1465° F.for 20 hours, two samples of the low sodium-USY zeolite catalysts(“LS-USY”) of the prior art and one sample of the low sodium-EMY zeolitecatalysts (“LS-EMY”) catalysts as embodied by the present invention weretested by catalytically cracking a typical FCC hydrocarbon feedstock inthe ACE unit at the following conditions:

TABLE 5A Hydrocarbon Feedstock Properties (Example 4) Feedstock PropertyValue Carbon 86.42 wt % Hydrogen 10.38 wt % Sulfur 1.47 wt % Nitrogen1281 ppm Basic Nitrogen 358 ppm Bromine Number 17.94 Refractive Index @70° C. 1.49 Specific Gravity of Liquids @ 70° C. 0.897 Molecular Weight(fp depression) 333 g/mol % 650- Boiling Point Material 23 wt %

TABLE 5B ACE Testing Conditions (Example 4) Parameter Value/RangeCat/Oil Ratio 3.5 to 8.5 Reactor Temperature 990° F. RegeneratorTemperature 1300° F. Feed Rate 1.82 g/min Catalyst Strip Time 400 secLiquid Strip Time 420 sec

The cat-to-oil ratios and product yields were normalized to a constantcoke yield of 3 wt % as a standard for comparison and these results areshown in FIGS. 6A, 6B, 7A, and 7B.

FIG. 6A compares the results of the LS-USY and LS-EMY catalysts tests(as normalized to 3 wt % coke yield). For ease of interpretation, theresults from the two (2) LS-USY catalysts tests were combined and shownas single values. The product values are shown in wt % of the totalhydrocarbon feed. The “conversion” value is calculated by the: Totalfeed (i.e., 100 wt %) minus the wt % of 430° F.+ liquid boiling pointmaterial in the product. Please note that the “wt % of 430° F.+ liquidboiling point material in the product” does not include coke. Theconversion value is shown in %.

For clarity purposes, FIG. 6B shows the arithmetic difference betweenthe “LS-EMY” value from the data in FIG. 6A and the “LS-USY” value fromthe data in FIG. 6A.

FIG. 7A compares the results of the ULS-USY and ULS-EMY catalysts tests(as normalized to 3 wt % coke yield). For ease of interpretation, theresults from the two (2) ULS-USY catalysts tests were combined and shownas single values. The values are shown in similar units as described inFIG. 6A, above.

FIG. 7B, similar to FIG. 6B, shows the arithmetic difference between the“ULS-EMY” value from the data in FIG. 7A and the “ULS-USY” value fromthe data in FIG. 7A.

Example 5

In this example, catalyst samples of FCC cracking catalysts werefabricated from comparable USY zeolite catalysis (“USY catalysts”) ofthe prior art and embodiments of the EMY zeolite catalysts (“EMYcatalysts”) of the present invention were fabricated with a matrix of apeptized aluminum oxide (Al₂O₃), a rare earth oxide, (RE₂O₃), and clay.All of these catalysts were made with a matrix comprised of 30 wt %peptized aluminum oxide (Al₂O₃), 1.7 wt % rare earth oxide, (RE₂O₃), 25wt % either USY or EMY zeolite, with the balance clay.

All of the catalysts of this example were made by preparing peptizedalumina by mixing a 20 wt % slurry of pseudoboehmite with 0.3 mols ofHCl per mol of Al₂O₃. 25% zeolite, 30% peptized alumina, 5% colloidalsilica and 1.7% RE₂O₃ from RECl₃ and clay were mixed for about 10minutes. The mixture was milled in a ball mill to reduce particle sizeand then dried in a catalyst spray dryer operated at 650° F. inlet and300° F. outlet temperatures. The spray dried catalyst was calcined at750° F., washed to lower Na₂O, filtered and rinsed with deionized waterand oven dried.

The finished catalysts were steam deactivated at approximately 1465° F.for 20 hours. The properties of the fresh catalysts andsteam-deactivated catalysts fabricated in this Example are shown in theTable 3.

Example 6

In this example, the catalyst samples from Example 5 were tested in alaboratory scale ACE unit under conditions simulating fluidizedcatalytic cracking (“FCC”) process conditions. The catalysts of Examplewere tested by catalytically cracking a typical FCC hydrocarbonfeedstock (same feedstock composition as in Example 4, Table 5A) in theACE unit at the following conditions:

TABLE 6 ACE Testing Conditions (Example 6) Parameter Value/Range Cat/OilRatio 4 to 8 Reactor Temperature 980° F. Feed Rate 3 g/min CatalystStrip Time 400 sec Liquid Strip Time 400 sec

The cat-to-oil ratios and product yields were normalized to a constantcoke yield of 3 wt % as a standard for comparison and these results areshown in FIGS. 10A and 10B.

FIG. 10A compares the results of the USY and EMY aluminum oxidescatalysts tests (as normalized to 3 wt % coke yield). For ease ofinterpretation, the results from the two (2) LS-USY catalysts tests werecombined and shown as single values. The product values are shown in wt% of the total hydrocarbon feed. The “conversion” value is calculated bythe: Total feed (i.e., 100 wt %) minus the wt % of 430° F.+ liquidboiling point material in the product. Please note that the “wt % of430° F.+ liquid boiling point material in the product” does not includecoke. The conversion value is shown in %.

For clarity purposes, FIG. 10B shows the arithmetic difference betweenthe EMY catalyst values from the data in FIG. 10A and the USY catalystvalues from the data in FIG. 6A.

1. A fluidized catalytic cracking catalyst comprised of: a Y zeolitewith a Large Mesopore Volume of at least about 0.03 cm³/g and a SmallMesopore Peak of less than about 0.15 cm³/g; and an inorganic matrix. 2.The catalyst of claim 1, wherein the zeolite has a Large-to-Small PoreVolume Ratio of at least about 4.0.
 3. The catalyst of claim 1, whereinthe unit cell size of the zeolite is less than about 24.45 Angstroms. 4.The catalyst of claim 1, wherein the inorganic matrix is comprised ofoxides of silicon, aluminum or combinations thereof.
 5. The catalyst ofclaim 1, wherein the inorganic matrix is comprised of a peptizedalumina.
 6. The catalyst of claim 1, wherein the catalyst is furthercomprised of a clay.
 7. The catalyst of claim 6, wherein the clay isselected from kaolin, bentonite, hectorite, sepiolite, and attapulgite.8. The catalyst of claim 1, wherein the catalyst has a 40 Å Peak of lessthan about 0.15 cm³/g.
 9. The catalyst of claim 1, wherein the inorganicmatrix is comprised of an alumina phase selected from species ofaluminum oxyhydroxides-γ-alumina, boehmite, pseudo-boehmite, diaspore,and transitional aluminas such as α-alumina, β-alumina, γ-alumina,δ-alumina, ε-alumina, κ-alumina, and ρ-alumina.
 10. The catalyst ofclaim 9, wherein the alumina phase is gibbsite, bayerite, norstrandite,or doyelite.
 11. The catalyst of claim 1, wherein inorganic matrix alsocontains phosphorous or aluminum phosphate.
 12. The catalyst of claim 1,wherein the catalyst is further comprised of a medium-pore zeolite withan average pore diameter less than about 0.7 nm.
 13. The catalyst ofclaim 1, wherein the precursor of the zeolite is subjected to a hightemperature steam calcination step at a temperature from about 1200° F.to about 1500 wherein the temperature of the zeolite precursor is within50° F. of the high temperature steam calcination temperature in lessthan 5 minutes.
 14. The catalyst of claim 1, wherein the Na₂O content ofthe precursor of the zeolite prior to the high temperature steamcalcination step is from about 2 to about 5 wt % of the total precursorweight on a dry basis.
 15. The catalyst of claim 2, wherein the SmallMesopore Peak of the zeolite is less than about 0.13 cm³/g.
 16. Thecatalyst of claim 1, wherein the catalyst has a 40 Å Peak of less thanabout 0.13 cm³/g.
 17. The catalyst of claim 16, wherein the LargeMesopore Volume of the zeolite is at least about 0.05 cm³/g.
 18. Thecatalyst of claim 2, wherein the Large Mesopore Volume of the zeoliteand the Small Mesopore Peak of the zeolite are measured in the asfabricated zeolite.
 19. The catalyst of claim 2, wherein the LargeMesopore Volume of the zeolite and the Small Mesopore Peak of thezeolite are measured after high temperature steam deactivation of thecatalyst.
 20. The catalyst of claim 1, wherein the inorganic matrix isfurther comprised of a rare-earth element.
 21. The catalyst of claim 1,wherein the zeolite is comprised of a rare-earth element.
 22. A methodof making a low small mesopore peak fluidized catalytic crackingcatalyst, comprising the steps of: a) combining a binder precursorselected from a silica, an alumina, or a combination thereof, with aclay and a zeolite to form a catalyst mixture; and b) drying thecatalyst mixture to form a catalyst; wherein the zeolite is a Y zeolitewith a Large Mesopore Volume of at least about 0.03 cm³/g and a SmallMesopore Peak of less than about 0.15 cm³/g.
 23. The method of claim 22,wherein the binder precursor is selected from a colloidal silica, silicagel, a silica sol, or a combination thereof.
 24. The method of claim 22,wherein the binder precursor is selected from a colloidal alumina,alumina gel, a silica sol, or a combination thereof.
 25. The method ofclaim 22, wherein the binder precursor is peptized alumina.
 26. Themethod of claim 25, wherein catalyst mixture also comprises a silica.27. The method of claim 22, wherein the clay is selected from kaolin,bentonite, and combinations thereof.
 28. The method of claim 22, whereinthe catalyst mixture is milled prior to drying the catalyst in step b).29. The method of claim 22, wherein the catalyst is dried by spraydrying the catalyst mixture at a temperature from about 300° F. to about650° F.
 30. The method of claim 22, wherein the dried catalyst is sievedto an average particle size from about 20 microns to about 150 microns.31. The method of claim 22, wherein the zeolite has a Large-to-SmallPore Volume Ratio of at least about 4.0.
 32. The method of claim 22,wherein the unit cell size of the zeolite is less than about 24.45Angstroms.
 33. The method of claim 2, wherein the catalyst after dryinghas a 40 Å Peak of less than about 0.13 cm³/g.
 34. The method of claim22, wherein the catalyst mixture is further comprised of a rare-earthelement.